Hobbing machine



o. E. STAPLES HOBBING MACHINE i 2 Sheets- 1 June 28! 1 Filed Jan 2 1956 NV R' 07/3 E JTAPLES ATTORNEYS Patented June 28, 1938 s'rrss PATET OFFICE HOBB'ING MACHINE Application January 2, 1936, Serial No. 57,130

1 Claim.

The present invention relates to hobbing machines and more particularly to the tool or hob heads thereof.

An object of the invention'is the provision of L a novel and improved tool or hob head in which the tool or hob spindle can be accurately set in a predetermined position, or moved axially a pre-.

, duces the most accurate work, with a maximum amount of accuracy in a minimum amount of time.

Prior to the present invention the hob was usually set by the cut and try method, whereas in machines of the present invention, after the hob has been set initially it can be moved to the successive positions at which it produces the most accurate work quickly and efliciently.

The present invention resides in certain novel details of construction and combinations and arrangements of parts, and further objects and advantages thereof will be apparent from the following description of the preferred embodiment described with reference to the accompanying drawings, forming a part of this specification, in which similar reference characters designate corresponding parts throughout the several views, and in which Fig. 1 is a perspective view of a hobbing machine embodying the present invention;

Fig. 2 is a section through the tool or hob head taken on a substantially horizontal plane through the spindle axis, and

Fig. 3 is a partial end view of the tool or hob head looking from the bottom as viewed in Fig. 2.

The present invention has special utility in hobbing machines of the type illustrated in a copending application of Frank H. Adams, Serial No. 729,118, filed June 5, 1934, entitled Hobbing machine and is shown herein as embodied in such a machine. Of course it is to be understood that the invention can be otherwise embodied, that the preferred embodiment shown is merely illustrative thereof, and that I do not wish to be limited to the particular construction shown.

Referring to the drawings, the hobbing machine shown therein is identical with that shown in the aforesaid application, with the exception of the tool or hob head, and a detailed description of the machine, with the exception of the tool or hob head, will not be given. The duplicate parts herein referred to are designated by the same reference characters and for a complete description of the remainder of the machine reference is made to the aforesaid application.

Briefly stated the machine shown is of general vertical construction, and comprises a frame B supported on a base A and provided with a work head C slidably supported on vertically spaced ways I3 and I4 formed on the frame B at the top and bottom thereof. The work head C carries a work spindle 3E] rotatably supported therein and driven in predetermined timed relation to the rotation of the tool or hob spindle by the main drive motor of the machine in a manner already known to the art. The work head is moved vertically to advance the work to the tool or hob and then fed past the same at a reduced speed through the medium of a cooperating lead screw and nut I55 and I56, respectively. The lead screw I55 is rotatably supported in the work head and is driven at a relatively slow speed in predetermined timed relation to the rotation of the tool and work spindle from the work spindle drive. The nut I56 is rotatably supported in a bracket I51, bolted or otherwise secured to the base A, and is adapted to be rotated at a relatiyely high speed through the medium of a self locking worm and worm wheel drive by a reversible motor supported by the base A and positioned within the frame 3.

The tool or hob head designated generally by the reference character D, comprises a tool or hob head slide I supported on horizontal ways IZI formed integral with the frame B intermediate the vertically spaced ways I3 and I4, and a tool or hob head housing 2 I I! rotatably supported by the hob head slide coaxial with the main drive shaft 64 of the machine. The tool or hob arbor or spindle 2i I is carried by the hob head housing 2H! and is adapted to be angularly adjusted about a horizontal axis by virtue of the adjustable connection between the tool or hob head slide and the tool or hob head housing.

Both the main drive motor and the motor for driving the nut I56 are preferably three phase alternating current motors and the latter is reversible. The motors are controlled by upper and lower limit switches I90 and IQI, respectively, and the start-stop push button switch I92. The limit switches I90 and I9! are operated and controlled by adjustable stops 2B0, 20! and 202 carried by the work head C. A precision gauge designated. generally by the reference character G is provided for accurately positioning the hob head axially of the work.

In the present instance, as clearly shown in Fig. 2, the tool or hob arbor 2! I, to the rear of the hob 2i 2, is slidably supported in a sleeve 2M, and. projects therethrough towards the rear through a gear 2 l5 and. into a sleeve cap H6. The sleeve 2M, gear H5 and cap 2H5 are bolted together as by bolts 2!? and form a unit or tubular-like member closed at one end within which the tool or hob arbor 2H is slidably but not-rotatably splined. The bolts project through suitable apertures in the gear 2H5 and sleeve cap 216, and are threaded into tapped apertures in a flange 222 formed integral with the sleeve 2M. The sleeve 2%, and in turn the aforesaid unit including the sleeve, gear and. sleeve cap, are rotatably supported by anti-friction bearings 22! in a suitable aperture 222 in the tool or hob head housing 2H! and the rear end of the tool or hob spindle is externally splined to the hob of the gear 2 i 5 by vitrue of which connection it is driven in predetermined timed relation to the rotation of the work spindle through the gear 2l5 and pinion 223 continuously in mesh therewith. The pinion 223 is formed integral with a short shaft 225 rotatably supported in the tool or hob head housing 253 by anti-frictionbearings 226, and driven from the main drive shaft 64 through the miter gears i28 and 929. I

The tool or hob spindle 2!! is adapted to be adjusted or moved axially within the sleeve 2M,

etc. for the purpose of setting the hob etc., by

a threaded shaft 238 rotatably supported in the cap 2N and threaded into a tapped. counterbore in the rear end of the spindle. Longitudinal movement of the shaft 23!] is prevented by a flange 23! formed integral therewith and retained in a counterbore formed in the bottom of the cap member 256 by a washer 232 held in position by a spacer collar 233. A dial 235 provided with appropriate graduations and carried by the shaft 238 to the rear of the cap 2l6 provides means for quickly and accurately moving the spindle a predetermined amount or setting the same in a predetermined position. In the embodiment shown the dial 235 is detachably secured to the shaft 238 by a set screw 236 2H and the splined connection between the spindle 2H and the gear 2E5. An elongated jam screw 240 projecting through the shaft 230 and having threaded engagement therewith is provided for taking up any possible lost motion in the threaded connection between the spindle 2H and the shaft 235. After the hob has been set and the shaft 236 secured in the desired position, the screw 245 is turned down until the lower end thereof jams against the bottom of the aperture in the spindle into which the shaft 230 projects. The gears H5, 223 etc. are enclosed by a housing 2 bolted to the rear end of the housing 2 [0.

The front end of the tool or hob spindle which is of reduced diameter is rotatably supported through the medium of a bushing 245 in a steady rest bushing 246 keyed in a steady rest or member 241 of general cylindrical shape. The member 241 has two slots or notches cut in opposite sides thereof by virtue of which it is retained in an elongated cylindrical groove 248 in the tool or hob head housing 210 by clamp members 249. The clamp members 249 are held in position and operated to clamp and release the member 24! by a plurality of studs 250 provided with clamp nuts 25!, and are cut away underneath as clearly shown in Fig. 3 in such a manner that the one edge thereof engages the member 241, while the other edge is fulcrumed on the member 2l0. The hob is positioned on the reduced end of the spindle 2H and is clamped between the shoulder formed by the reduced portion, and the bushing 245 by a nut 253 threaded onv the end of the spindle. When it is desired to adjust or move the tool or hob spindle the clamp nuts 25! are backed oiT the studs 250 and the member 24'! is then free to slide in the groove 248 underneath the clamp members 249. After the hob has been set the clamp nuts 25| are again tightened.

From the foregoing description of the preferred embodiment of the invention, it will be apparent that the aforesaid objects of the invention have been accomplished, and that a hob head or hobbing machine has been provided in which the tool or hob spindle can be quickly and accurately set in a predetermined position or moved a predetermined amount as desired. While the preferred embodiment of the invention has been shown and described, it is merely illustrative of the invention and I do not wish to be limited to the particular construction shown which may be varied within the scope of the invention, and. I particularly point out and claim as my invention the following.

I claim:

In a hobbing machine the combination of a tool or hob head housing, a tubular-like mem-- ber closed at one end rotatably supported in said housing, a tool or hob arbor slidably splined in said tubular-like member and having a tapped aperture in the end thereof adjacent the closed end of said tubular-like member, means for rotating said tubular-like member, a cylindrical.

member having a tapped aperture extending therethrough threaded into said aperture in said tool or hob arbor, means for rotatably supporting said cylindrical member in the" closed end of said tubular-like member, means for preventing longitudinal movement of said cylindrical member relative to said tubular-like member, a dial provided with suitable indicia secured to said cylindrical member, and an elongated bolt threaded in said tapped aperture in said cylindrical member with the lower end thereof engaging the bottom of said aperture in said tool or hob arbor.

OTIS E. STAPLES. 

